MAX4588 Datasheet, PDF (16/20 Pages) Maxim Integrated Products – Low-Voltage, High-Isolation, Dual 4-Channel RF/Video Multiplexer

Low-Voltage, High-Isolation,
Dual 4-Channel RF/Video Multiplexer
Power-On Reset (POR)
The MAX4588 has internal circuitry to guarantee a
known state on power-up. In the default state, A0 = A1
= A2 = 0, disable = 1, and all switches are off. This
state is equivalent to asserting RS during normal opera-
tion.
Serial Operation
The serial mode is activated by driving the SER/PAR
input pin to a logic high. The data is then entered using a
normal SPI/MICROWIRE write operation. Refer to Figure
7 for a detailed diagram of the serial-interface logic.
There are four flip-flops in the shift register, with the out-
put of the fourth shift register being output on the DOUT
pin. Note: DOUT changes on the rising edge of SCLK.
This allows cascading of multiple MAX4588s using only
one chip-select line. For example, one 16-bit write could
load the shift registers of four cascaded MAX4588s. The
data from the shift register is moved to the internal con-
trol latches only upon the rising edge of CS, so all four
MAX4588s change state simultaneously.
Parallel Operation
The parallel mode is activated by driving SER/PAR to a
logic low. The MAX4588 is programmed by a latched
parallel bus scheme. Refer to Figure 6 for a detailed
diagram of the parallel-interface logic. Note that 4/8 is
not latched. It is best to hard-wire 4/8 to a known state
for the desired mode of operation, or to use a dedicat-
ed microcontroller port pin.
Parallel Operation
Truth Tables
SER/PAR
A2
A1
A0
EN
LE
RS
4/ 8
SWITCH STATES
0
x
x
x
x
1
1
x
Maintain previous state.
x
x
x
x
x
x
0
x
All switches off, latches are cleared.
1
x
x
x
x
x
1
x
Serial Mode. Refer to Serial Operation
Truth Table.
0
x
x
x
0
0
1
x
All switches off.
0
0
0
0
1
0
1
0
Connects NO1 to COM1
0
0
0
1
1
0
1
0
Connects NO2 to COM1
0
0
1
0
1
0
1
0
Connects NO3 to COM1
0
0
1
1
1
0
1
0
Connects NO4 to COM1
0
1
0
0
1
0
1
0
Connects NO5 to COM2
0
1
0
1
1
0
1
0
Connects NO6 to COM2
0
1
1
0
1
0
1
0
Connects NO7 to COM2
0
1
1
1
1
0
1
0
Connects NO8 to COM2
0
x
0
0
1
0
1
1
Connect NO1 to COM1 and NO5 to COM2
0
x
0
1
1
0
1
1
Connect NO2 to COM1 and NO6 to COM2
0
x
1
0
1
0
1
1
Connect NO3 to COM1 and NO7 to COM2
0
x
1
1
1
0
1
1
Connect NO4 to COM1 and NO8 to COM2
x = Don’t Care
Note: 4/8 is not latched when LE is high. When LE is low, all latches are transparent. A2, A1, A0, and EN are latched.
Connect COM1 to COM2 externally for 1-of-8 single-ended operation.
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